How do you change a watch battery?

Watchmaking is often a story of passion. You love your timepieces, and they quickly become a little part of you. As time goes by and the minutes are carefully counted by your second hand, your watch battery may run out, and then time stops. Of course, this type of problem does not affect all watches. A mechanical watch, whether self-winding or manually wound, has no battery and instead operates with a barrel, escapement and regulating organ, so it is not affected. However, if you own a quartz timepiece in your watch collection, you will sooner or later face this problem.

So let’s see how to change a watch battery easily ?

Contents:

• Visit your watchmaking professional or favourite jeweller
• Changing your battery yourself: risks to consider
• The different types of case backs and the tools required
• Change your battery yourself in a few steps

Visit your watchmaking professional or favourite jeweller

We mention this because it seems important. Your timepiece’s battery has a lifespan, and replacing it yourself is not a trivial task. To ensure that a worn battery is replaced under the best possible conditions, the safest option is to make an appointment with a specialist.

Changing your battery yourself: risks to consider

The main danger is that your watch may no longer be waterproof, making it vulnerable to moisture. If you open your watch and do not replace the waterproof seal around the edge perfectly without damaging it, your watch will no longer be fully sealed. To ensure that your miniature clock is protected from water, moisture and all liquids, have this step carried out by a specialist. 

Did you know? Some watches advertised as water-resistant up to 100 m are sometimes completely without this seal.

You should know that it is best to avoid handling the battery with your fingers! Since they are conductive, the battery could discharge quickly and cause a short circuit. Wearing gloves will also prevent fingerprints, perspiration and dust.

To carry out these steps, it is advisable to use tweezers, plastic tweezers or a Rodico-type cleaning putty.

Be sure to clean the battery with a soft cloth before putting it back in place. 

If any of you would like to give it a try, here is a short tutorial to help you.

The different types of case backs and the tools required

The first thing to know is that there are three different types of case backs, and they do not all open in the same way. So there is no need to rush out and buy the entire kit of the perfect amateur jeweller; instead, take a look at which type you are dealing with.

• The snap-on case back opens with a watchmaker’s knife: however, be careful, as these case backs can be difficult to close again. To avoid damaging your timepiece when replacing its battery, you will need a special press that applies evenly distributed pressure so as not to break the crystal on your little clock’s dial.
• The screw-down case back opens with a wrench: there is not much difficulty here, except that you need to check the diameter and width of the notches and position the tool correctly, otherwise a scratch can happen quickly.
• The independent screw case back : all you need is a good-quality screwdriver of the right size to avoid damaging the screw head, which is often very fine and delicate.

To replace your watch battery safely and avoid damaging your item during the process, be sure to follow these steps:

1. Avoid touching the watch movement with your fingers as much as possible.
2. Make sure to  reposition the “casing ring” (“case ring”) before closing the case back.
3. Check the condition of the waterproof seal and do not forget to reposition it properly. If you have any doubts about it, visit your watchmaker for professional advice. If liquid gets into the case, time stands still.

Change your battery yourself in a few steps 

• Open the case: depending on the type of case identified, you will need to unscrew it using an adjustable wrench or a good-quality screwdriver, or pry it open with a knife. Carefully locate the slots to position your tool correctly. 
• Once the watch is open, take a pair of tweezers, remove the casing ring before replacing your watch battery with an identical battery. Make sure to identify the poles of the battery "+" and "-". It must be identical in every respect: component, size and voltage.

There are 3 types of batteries: silver oxide, alkaline and lithium batteries.

• Silver oxide batteries can be identified by the letter S engraved on them. This type of battery provides a voltage of 1.55 volts.
• Alkaline batteries look like silver oxide batteries. Marked with the letter L, they deliver a voltage of 1.50 volts.
• Lithium batteries found in many analogue watches are marked with the letter C and provide a voltage of 3 volts. 

Finally, a battery’s diameter differs from one watch to another. Be sure to identify the one that matches your timepiece model.

Some watches with screw-down or snap-on case backs have a tab that keeps the battery securely in place. Don’t panic: it can easily be removed with your fingers or tweezers; simply use it as a lever to prevent the tab from suddenly flying away.

The final step in this tutorial is to close your watch by putting the back cover back on. To do this:  

• On the back of the watch, locate the case ring notch near the crown stem and replace the casing ring.

Also note that not all batteries are equal. Your watch’s features (alarm, stopwatch, etc.) affect your battery’s lifespan.

Want to know more about your watches? Take a look at our article on the differences between automatic and quartz watches.